The proposed project has two components: 1) a study of the functional role of inhibition in somesthesis, and 2) a study of reflex, motor and sensory pathways in ganglia of the marine mollusc Aplysia. The first project involves both psychophysical and electrophysiological methods and the attempt is made to understand tactile sensory illusions and distortions. The second project combines behavioral, electrophysiological and biochemical analyses of neuronal plasticity in simple cellular systems.